Color camera tube having color strip filter and an index electrode

ABSTRACT

A color camera tube including, a target assembly disposed on the inner surface of the faceplate and having a color strip filter and an index electrode, at least one conductive pin member embedded in the envelope and electrically connected to the index electrode.

United States-"Patent [1 .1

Tomii et al.

[ Dec. 24, 1974 COLOR CAMERA TUBE HAVING COLOR STRIP FILTER AND AN INDEX ELECTRODE Inventors: Kaoru Tomii; Hiroshi Miyama, both of Osaka, Japan Assignee: Matsushita Electric Industrial Company Limited, Osaka, Japan Filed: Sept. 29, 1972 Appl. No.: 293,515

[30] Foreign Application Priority Data Sept. 29, 1971 Japan 46-76473 May 24, 1972 Japan 47-52029 May 24, 1972 Japan", 47-52030 May 24, 1972 Japan 47-52031 May 24, 1972 Japan l 47-52032 US. Cl. 313/65 R, 313/69 C, 313/92 Bl, 313/283, 313/331 Int. Cl. H0lj 31/26 Field of Search 313/65 R, 65 T, 69 C, 92 B1, 313/64 R, 329, 331, 283

References Cited UNITED STATES PATENTS 9/1955 Coltman 313/65 R Van Overbeek 313/92 B1 3,051,861 8/1962 Ridgeway 313/65 R 3,066,239 11/1962 Bocciarelli 313/92 B1 3,379,822 4/1968 Haans et al. 313/64 3,443,139 5/1969 Thompson 313/92 B1 3,582,978 6/1971 Petersen 313/64 3,675,062 7/1972 Flaschc 313/65 3,714,488 1/1973 Kato 313/65 R 3,721,752 3/1973 Kakizaki.... 178/54 ST 3,727,087 4/1973 Sutton 313/92 R FOREIGN PATENTS OR APPLICATIONS 1,155,477 10/1963 Germany 313/92 Bl 1,038,765 8/1966 Great Britain 313/92 Bl Primary ExaminerJames W. Lawrence Assistant Examiner-Saxfield Chatmon, Jr.

[57] ABSTRACT A color camera tube including, a target assembly disposed on the inner surface of the faceplate and having a color strip filter and an index electrode, at least one conductive pin member embedded in the envelope and electrically connected to the index electrode.

5 Claims, 16 Drawing Figures PATENTEB DEC 2 41974 SHEET 30F 8 PATENTED [ED241974 SHEET 5 BF 8 PATENTED UEC24|974 SHEET 8 0? 8 llllllll I I I PATENTED BEC24|974 SHEET 8 OF 8 Fig. /6

COLOR CAMERA TUBE HAVING COLOR STRIP FILTER AND AN INDEX ELECTRODE The present invention is directed to color camera tube and more particularly to a color camera tube which includes a color strip filter and an index electrode.

An improved color camera tube has recently been developed, which can produce a color image signal containing the chrominance and the luminance components without cooperation with any other devices. The particular color camera tube includes a color strip filter usually placed on the inner surface of the faceplate thereof for spacially modulating color components contained in a color image focussed on the faceplate, a photo-conductive layer disposed on the color strip filter for converting the spacially modulated color image into an color image signal containing color components, and an index electrode positioned in the vicinity of the photo-conductive layer for producing an index signal which is useful for seperating the color components from one another. The color strip filter is constituted by a plurality of color strips arranged in a certain order. An electron beam emitted from the electron gun positioned opposite to the faceplate is horizontally and vertically deflected by the deflection element placed on the envelope of the tube so that the electron beam scans the photo-conductive layer and the index electrode whereby the color image signal and the index signal are produced in the photo-conductive layer and the index electrode, respectively. Although the index electrode should be correctly positioned at a desired position relative to the color strip filter, it is, in practice, difficult to fasten the index electrode to a desired place. In addition, a lead for leading out the index pulse signal produced in the index electrode should be formed in the envelope of the tube in addition to the lead for leading out the color image signal produced in the photoconductive layer.

It is accordingly an object of the invention to provide a color camera tube which has an improved construction feasible for desiredly aligning the index electrode with respect to the color strip filter.

It is another object to provide a color camera tube which can be readily manufactured.

These and other objects, features and advantages of the invention will be better understood from the following more detailed description with reference to the accompanying drawings in which:

FIG. 1 is a sectional view of a conventional color camera tube including a color strip filter and an index electrode FIG. 2 is a sectional view of a color camera tube according to the invention.

FIG. 3 is a front end view of the tube of FIG. 2.

FIG. 4 is a sectional view of another color camera tube according to the invention.

FIG. 5 is a front end view of the tube of FIG. 4.

FIG. 6 is'a fragmentary perspective view of a target assembly of the tube of FIG. 4.

FIG. 7 is a sectional view. of a color camera system employing the tube of FIG. 4.

FIG. 8 is a fragmentary sectional view of another color camera tube according to the invention.

FIG. 9 is a front end view of the tube of FIG. 8.

FIG. 10 is a color camera system employing the tube of FIG. 8.

FIG. 11 is a fragmentary sectional view of another color camera tube according to the invention.

FIG. 12 is a sectional view of another color camera tube according to the invention. 7

FIG. 13 is a front end view of the tube of FIG. 12.

FIG. 14 is a sectional view of another color camera tube according to the invention.

FIG. 15 is a front end view of the tube of FIG. 14.

FIG. 16 is a sectional view of another color camera tube according to the invention.

Like characters of reference designate like parts in the views.

Referring now to the drawings and more specifically to FIG. 1, there is shown a conventional color camera tube 10 which includes-an evacuated envelope 11 usually made of a glass material and having a transparent faceplate 12. A color strip filter 13 consisting of plurality of color strips is disposed on the inner surface of the faceplate 12. The color strip filter l3 specially modulates each color component contained in an image focussed on the faceplate through a suitable optical arr'angement (notshown). A transparent electroconductive layer 14 is disposed on the color strip filter 13, which layer 14 is connected an electrode 15 piercing through the side wall of the envelope 11. A photoconductive layer 16 is disposed on the transparent conductive layer 14, so that the photo-conductive layer 16 converts the image spacially modulated and passed through the transparent conductive layer 14 into an electric signal, that is image signal. An index electrode 17 consisting of a plurality of parallel conductive strips is positioned in the vicinity of the photo-conductive layer 16. The index electrode 17 is connected withanother electrode 18 piercing through the side wall of the envelope 11. An electron gun assembly 19 is positioned within the envelope 11 so as to strike the photoconductive layer 16 with an electron beam indicated by an arrow 20. The electron gun assembly 19 consists of a cathode 21 placed at an opposite side to the faceplate l2, and first, second, third and fourth grids 22, 23, 24 and 25 arranged in the order named. The grids 22, 23, 24 and 25 cooperate with focusing and alignment coils 26 and 27 surrounding the envelope 11 so as to converge electrons emanated from the cathode 21 into the electron beam 20 The electron beam 20 is horizontally and vertically deflected by a deflecting coil 28 so that the electron beam scans the photo-conductive layer 16 and the index electrode 17, whereby camera signal and index signal appear at the electrodes 15 and 18, respectively. The electrode 15 is connected through a resistor 29, and a bias d-c source 30 to the ground and through a coupling capacitor 31 to a camera signal output terminal 32. The electrode 18 is connected through resistor 33 and a bias d-c source 34 to the ground and through a coupling capacitor 35 to an index signal output terminal 36-. The camera and index signals are therefore picked up through the terminals 32 and 36 by a suitable circuit (not shown) and converted into a video signal to be utilised by a television transmission A system.

Since the index signal is used for detecting the color components contained in the camera signal, the position of each strip of the index electrode 17 should be correctly positioned at a desired position relative to the position of each color strip of the color strip filter 13. However, it is, in manufacture, difficult to fasten the index electrode 17 in a desired position. Furthermore,

it is usually difficult to form the electrode 18 in the side wall of the envelope 11 although the electrode can be formed by an indium ring.

So as to solve the above-stated problems, an improved color camera tube is provided by the invention.

FIGS. 2 and 3 illustrate a color camera tube 40 according to the invention, which comprises an envelope 11 with open and closed ends. A transparent faceplate 12 is attached by way of a conductive annular member 41 so as to hermetically seal the open end of the envelope 11. Thereupon, the envelope 11 can be evacuated for the sake of free advancement of an electron beam which may be generated in the envelope 11. When the annular member 41 is made of indium, the attachment of the faceplate 12 to the open end of the envelope 11 can be performed by pressure welding the annular member 41. The faceplate 12, annular member 41 and envelope may be assembled by using an adhesive agent. A conductive signal ring 42 is coupled on the annular member 41 so as to make sturdy the assembly of the faceplate 12, the annular member'4l and the envelope 11 and to serve as an electrode for conveying a signal appearing in the annular member 41. A pair of conductive pin members 43 and 43' are embedded in portions outside the effective area of the faceplate 12 in such a manner as to extend from the outer to inner surfaces of the faceplate 12 and protrude from the inner surface of the faceplate 12 inward to a certain height. The pin members are to be made of such a material as to have generally the same coefficient of thermal expansion as that of the faceplate 12. A color strip filter 13 is dising members 43 and 43, and the color camera tube 40 are readily manufactured and economical.

FIGS. 4 and 5 illustrate another color camera tube 50 according to the invention, which comprises an envelope 11 with an open end. A transparent faceplate I2 is adhered onto the open end so as to hermetically seal the envelope 11. A ring 42 is coupled on the boundary between the faceplate 12 and the open end of the envelope 1 1 so as to ensure the interconnection between the faceplate l2 and the envelope 11. A pair of conductive pin members 43 and 43 are embedded in portions outsid ethe effective beam scanning area of the faceplate 12 in such a manner as to extend from the outer to inner surfaces of the faceplate 12. Outer ends of the pin members 43 and 43' are respectively connected to a pair of electrodes 18 and 18 formed on the outer surface of the faceplate 12. The electrodes 18 and 18' are circumferentially elongated through a predetermined length as especially seen from FIG. 5. A color strip filter 13 is disposed on the inner surface of the faceplate 12. On the color strip filter 13 is disposed a combshaped index electrode 17 on which a photoconductive layer 61 is disposed. The index electrode 17 consists of a pair of comb-shaped electrodes 17a and 17b which 43. The reed members 44 and 44 are preferably made posed on the inner surface of the faceplate 12. On the color strip filter 13 is disposed a transparent conductive layer 14 which is electrically connected to the annular member 41. A photo-conductive layer 16 is disposed on the transparent conductive layer 14. An index electrode 17 is mounted on the inner ends of the pin mem bers 43 and 43', so that the index electrode 17 is electrically connected to the pin members 43 and 43' Outer ends of the pin members 43 and 43 are connected to index signal electrode 18 formed on the outer surface of the faceplate. An electron gun assembly 19 consisting of the same elements as that in the camera tube of FIG. 1 is positioned within the envelope 11. The index signal electrode 18 is grounded through a resistor 29 and a bias d-c source 30 and connected through a coupling capacitor 31 to an index signal terminal 32. The annular member 41 is grounded through a resistor 33 and a bias d-c source 34 and connected through a coupling capacitor 35 to a camera signal terminal 36. Focusing, alignment and deflecting coils (not shown) the same as that of the tube of FIG. 1 are provided around the envelope 1 1 so as to produce a desired electron beam indicated by 20 and deflect the electron beam.

When, in operation, the electron beam 20 scans the photo-conductive layer 16 and index electrode 17, video and index signals are produced in the layer 16 and electrode 17 and appear on the terminals 36 and 32. respectively.

It should be now appreciated that the pin members 43 and 43' make. easy to position the index electrode 17 at a desired position and serve as leads for comveying the index signal produced in the index electrode by the scanning of the electron beam 20. Accordingly, a usual sealing member can be usedfor the annular sealof agraphite or conductive silver wating material. Since the strips of the comb-shaped electrodes of the electrode 17 are arranged at a predetermined pitch relative to the pitch of the color strip of the color strip filter l6, signals constituted by pulses appearingat a certain repetition rate are produced in the comb-shaped electrodes, which signals are led out through the pin members 43 and 43, respectively. The remaining portion of the tube of FIGS. 4 and 5 is constructed in the same manner as that of FIGS. 2 and 3. The signals from the comb-shaped electrodes 17a and 17b are first preamplified and added to each otherso as to obtain a video signal and subtracted one from another so as to obtain an index signal.

FIG. 7 shows color camera system 55 employing the color camera tube shown in FIGSQ4 and 5. The'system comprises ahousing 56 having a projected open end portion 57. The color camera tube 50 is firmly fixed by means of support members 58 and 58' mounted on the inner wall of the housing 56, so that the faceplate 12 views an aperture defined by the open end portion 57. Anoptical arrangement 59 is placed within the aperture thereby to focus an optical image to be picked up onto the faceplate 12. A pair of conductive resilient members 60 and 60' are mounted on the support members 58 and 58, respectively, so that the resilient members 60 and 60' are contacted to the electrode 18 and 18 on the faceplate 12. Suitable circuit arrangement (not shown) for picking up signals appearing on the electrodes 18 and 18' are connected to the resilient'members 60 and 60'.

It is, in this instance, to be noted that since the electrodes l8 and 18' are elongated circumferentially, the alignment of contacting the resilient member 60 and 60 to the electrodes 18 and 18' can be readily achieved in manufacture of the system 55.

FIGS. 8 and 9 illustrate another color camera tube according to the invention, which comprises the same elements as that of FIGS. 4 and 5 and further comprises a cap member 66 having an aperture 67 and coupled with the front end portion of the envelope ll of the tube 65 in such a manner that the faceplate 12 is exposed through the aperture to the outside. The cap member 66 is prevented from releasing from the envelope 11 by means of screws 68 and 68'. A pair of conductive members 69 and 69 are fastened on the cap member 66 by means of screws 70 and 70'. The conductive members 69 and 69' respectively have reed shaped ends 69a and 69a inward radially extending to contact with the electrodes 18 and 18 and have the other ends69b and 6% extending on the peripheral wall of the cap member 66. a

FIG. 10 illustrates a color camera system 75 which comprises the color camera tube 65 shown in FIGS. 8 and 9, a housing 56 having the same shape as that ofthe system 55 shown in FIG. 7. A pair of support members 58 and 58 are fastened to the housing 56 which supports the color camera tube 65. A pair of conductive resilient members 60 and 60 are mounted on the support members 58 and 58' so that the resilient members 60 and 60 respectively contact with the conductive members 69 and 69'. Suitable circuit arrangements may be connected to the members 60 and 60 so as to pick up signals produced in the tube 65. It is, in this instance, to be noted that since the parts for the camera system using a usual monochrome camera tube can be used for the housing 56, the support members 58 and 58', and the resilient members 60 and 60', the camera system 75 can be economically manufactured.

FIG. 11 illustrates another color camera tube 80 according to the invention, which comprises the same elements and construction as that shown in FIGS. 8 and 9 except that the cap member 66 is threaded with the ring member 42.

FIGS. 12 and 13 show another colorcamera tube according to the invention which comprises the same ele- FIGS. 15 and 16 show another color camera tube 90 according to the invention which comprises the same elements construction as that of FIGS. 4 and 5 except that the pin members 43 and 43 are embeded in the side wall of the envelope 11 are connected through a pair of leads 91 and 91' to the comb-shaped electrodes of the signal electrode 17, respectively. A pair of elongated conductive layers 69 and 69' are coated on the peripheral wall of the envelope 11 in such a manner as to electrically connect with the pin members 43 and 43. The camera tube 90 can be used for the system 75 in stead of the tube 65.

FIG. 16 shows another color camera tube 95 according to the invention, which comprises the same elements and construction as that of FIGS. 14 and 15 except that a conductive annular member 41 interconnects between the faceplate l2 and the envelope 11 and a signal ring 42 is coupled on the annular member 41 and that only one pin member 43 is embeded inthe side wall of the envelope 11. One of the comb-shaped electrodes of the index electrode 17 is connected limited to the exact construction shown and described and that various changes and modifications may be made without departing from the spirit and scope of the invention, as defined in the appended claims.

What is claimed is:

1. In a color television camera tube adapted to be supported within a camera case, the tube having a cylindrical evacuated body, a face plate coupled to said body at one end thereof, a target assembly disposed on one side of said face plate and having a color filter, a photo conductive layer and a pair of index electrodes, the improvement which comprises a pair of electrically conductive studs embedded in said face plate and extending there through, first ends of said studs connected respectively to said index electrodes, the other ends of said studs projecting beyond a surface of said face plate, support members disposed between the camera case and the camera tube for supporting the camera tube body, and a pair of conductive resilient members mounted on said support members and con-.

tacting the other ends of said respective studs for electrically coupling said studs with said support members, thereby picking up electrical signals through said studs.

2. An arrangement as defined inclaim 1, wherein said index electrodes are comb-shaped electrodes.

3. In a color television camera tube adapted to be supported within a camera case, the tube having a cylindrical evacuated body, a face plate coupled to said body at one end thereof, a target assembly disposed on one side of said face plate and having a color filter, a photo conductive layer, and a pair of index electrodes, the improvement which comprises conductive pins embedded in the face plate and extending therethrough, a cap member provided on a coupled portion between the face plate and the cylindrical body, and a pair of terminal electrodes disposed on said cap member and connected to respective first ends of said pins, the other ends of said pins being connected respectively to said pair of index electrodes thereby picking up electric signals through the cap member and the terminal electrodes.

4. An arrangement as defined in claim 3, further comprising support members disposed between the camera case and the tube for supporting the camera tube body, and a pair of resilient conductive members respectively disposed between said terminal electrodes and said support members for electrically coupling said pair of terminal electrodes with said support members.

5. An arrangement as defined in claim 3 wherein said index electrodes are comb-shaped electrodes. 

1. In a color television camera tube adapted to be supported within a camera case, the tube having a cylindrical evacuated body, a face plate coupled to said body at one end thereof, a target assembly disposed on one side of said face plate and having a color filter, a photo conductive layer and a pair of index electrodes, the improvement which comprises a pair of electrically conductive studs embedded in said face plate and extending there through, first ends of said studs connected respectively to sAid index electrodes, the other ends of said studs projecting beyond a surface of said face plate, support members disposed between the camera case and the camera tube for supporting the camera tube body, and a pair of conductive resilient members mounted on said support members and contacting the other ends of said respective studs for electrically coupling said studs with said support members, thereby picking up electrical signals through said studs.
 2. An arrangement as defined in claim 1, wherein said index electrodes are comb-shaped electrodes.
 3. In a color television camera tube adapted to be supported within a camera case, the tube having a cylindrical evacuated body, a face plate coupled to said body at one end thereof, a target assembly disposed on one side of said face plate and having a color filter, a photo conductive layer, and a pair of index electrodes, the improvement which comprises conductive pins embedded in the face plate and extending therethrough, a cap member provided on a coupled portion between the face plate and the cylindrical body, and a pair of terminal electrodes disposed on said cap member and connected to respective first ends of said pins, the other ends of said pins being connected respectively to said pair of index electrodes thereby picking up electric signals through the cap member and the terminal electrodes.
 4. An arrangement as defined in claim 3, further comprising support members disposed between the camera case and the tube for supporting the camera tube body, and a pair of resilient conductive members respectively disposed between said terminal electrodes and said support members for electrically coupling said pair of terminal electrodes with said support members.
 5. An arrangement as defined in claim 3 wherein said index electrodes are comb-shaped electrodes. 